A mature, female cockatiel (Nymphicus hollandicus) was examined because of respiratory difficulties. Clinical and laboratory findings included ascites and evidence of hepatic disease (i.e., increased plasma bile acid concentrations, aspartate aminotransferase, and alkaline phosphatase activities). Plasma protein electrophoresis results were consistent with chronic-active inflammation. The albumin-to-globulin (A:G) ratio, calculated from plasma electrophoresis, was 0.3. Postmortem examination revealed severe hepatic fibrosis and a diffuse, interstitial, granulomatous lipid pneumonia.